Autoimmune Limbic Encephalitis with Neurogenic Stunned Myocardium

Autoimmune encephalitis can present itself in a wide multitude of ways, and it is often low on the clinician’s differential diagnosis list. Varied presentations make the diagnosis challenging, and a definitive diagnosis is only achieved by autoimmune antibody studies. Limbic encephalitis, a sub-type of autoimmune encephalitis, occurs due to inflammation of the limbic system of the brain and this could have either paraneoplastic or nonparaneoplastic aetiology. It often presents with rapid onset of confusion, memory impairment, mood changes, and frequently seizures. An unusual phenomenon rarely observed in autoimmune limbic encephalitis is the malfunction of the autonomic nervous system with a catecholamine surge that damages the myocardium to cause a neurogenic stunned myocardium. We present a case of a 48-year-old gentleman presenting with rapid cognitive decline and clinical evidence of heart failure, subsequently diagnosed as limbic encephalitis and neurogenic stunned myocardium. This clinical picture is exceedingly rare with only two previous cases reported in the literature.